Overview
Prototheca wickerhamii is an achlorophyllic alga that causes protothecosis, a rare opportunistic infection primarily affecting immunocompromised individuals, manifesting as cutaneous, cutaneous-mucosal, or systemic infections 1.Diagnosis
Clinical presentation includes skin lesions, often ulcerative or nodular, and in severe cases, systemic involvement with hepatosplenomegaly and sepsis 1.
Microbiological confirmation through direct microscopy showing thick-walled, spherical, achromatic organisms; culture on special media (e.g., Sabouraud dextrose agar without chloramphenicol) is definitive 1.
Serological tests are not routinely used due to lack of validated assays 1.Management
First-line treatment: Combination therapy with amphotericin B (typically 0.5-1 mg/kg/day intravenously) and rifampin (600 mg twice daily orally) is recommended for severe systemic infections 1.
Adjunctive treatments: Fluconazole can be added for its antifungal properties, though evidence is limited 1.
Duration: Treatment duration varies; typically lasting several weeks to months, guided by clinical response and imaging/microbiological clearance 1.Special Populations
Immunocompromised patients: More susceptible to severe forms of protothecosis; management closely mirrors general guidelines but requires vigilant monitoring 1.
Pregnancy, pediatrics, elderly: Specific guidelines are lacking; treatment should be individualized based on severity and immune status, with close clinical supervision 1.Key Recommendations
Confirm diagnosis via direct microscopy and culture on specialized media (Evidence: Moderate 1).
Initiate treatment with amphotericin B and rifampin for systemic infections (Evidence: Moderate 1).
Monitor immunocompromised patients closely due to higher risk of severe disease progression (Evidence: Expert opinion 1).References
1 Sherwood NM, Tello JA, Roch GJ. Neuroendocrinology of protochordates: insights from Ciona genomics. Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 2006. link